Advances in biomedical research funded by the NIH in our School of Arts and Sciences (SAS) and Engineering School require ready access to a state-of-the-art confocal laser scanning microscope. Numerous currently supported projects within Chemistry, Physics, Biology, and Bioengineering at the University of Pennsylvania would benefit from this instrument. These include in vivo studies of polymersomes and related polymeric "worms" (Bioengineering); incorporating multiple porphyrin-based fluorophores into such vesicles, and localizing molecular beacons within cells (Chemistry); fate mapping zebrafish development through ultraviolet uncaging of fluorophores and small molecules (Biology); and investigating soft materials, neuronal interactions, and photodynamic therapy (Physics). The assembled user group possesses considerable expertise in optical imaging techniques, and, in particular, confocal laser scanning microscopy (CLSM). Routine access to CLSM is crucial for validating the localization of polymeric assemblies, proteins, and drugs within living cells and animals. CLSM provides hundreds-of-nanometer resolution images of complex 3-dimensional structures, and allows the interrogation of molecules with light, either within living systems or soft materials. Recent advances in commercially available confocal microscopes place these instruments increasingly in the domain of Chemistry and Biophysics. The current lack of a confocal microscope within the Chemistry Department, and the shortage of general-access, state-of- the-art CLSM facilities available to physical scientists at Penn negatively impacts studies important to many NIH-supported programs. An urgent need for access to these new technologies and a few shared scientific goals have brought together investigators from four different departments for this proposal.